The formation mechanism of feldspar ovoids in rapakivi granites, chrome-spinellide nodules and orbicular olivine in peridotites. The role of mineral forming environment mobility for the implementation of normal mechanism of crystals growing
2. Mineralogical crystallography and crystal chemistry.
As it was observed during the process of ice crystallization in Baikal Lake, rounded shape of ice crystals originates under very strong wind, which forces them to rotate intensively, providing ideal conditions for normal mechanism of crystals growing. The patterns of rapakivi granites textures correlate with these observations – K-Na feldspar ovoids are flowed around by feldspar tabular crystals of the next generation. This, as well as concentric arrangement of biotite and hastingsite inclusions inside the ovoids, conformal to their external form, shows the growing of the ovoids in the melt during the process of rotation. Thus, ovoids in rapakivi granites grew up as oolites way. Probably, significant mobility of the mineral forming environment is the necessary condition for implementation of normal mechanism of crystal growing.
Keywords: normal mechanism of crystal growing, mobility of the mineral forming environment, feldspar ovoids, chrome-spinellides nodules, orbicular olivine.